Field of the Invention
The invention relates to a pixel unit, and more particularly, relates to a pixel unit of an organic electroluminescent display.
Description of Related Art
With advancement in display technologies, transparent displays have been gradually developed. A transparent display has a sufficient transparency rate, which enables a person to clearly watch a background image behind the transparent display. Since the transparent display may be applied to windows of buildings or cars, or may be used in showcase events, the transparent display has attracted great attention of the market. Generally, the transparent display may be classified into a self-illuminating type and a non self-illuminating type. Because the self-illuminating type transparent display does not need to dispose a backlight module that blocks part of a background image light beam, it is more suitable for applications in the field of the transparent display as compared to the non self-illuminating type transparent display.
The self-illuminating transparent display includes an organic electroluminescent display which utilizes an organic light emitting layer as a display medium. In order to cope with driving characteristics of the organic light emitting layer, the organic electroluminescent display is disposed with a power line coupled to the organic light emitting layer. In conventional technology, the power line and a data line are usually disposed inside a specific mesh region, such that light cannot easily pass through the mesh region. The background image light beam is non-uniformly blocked by the mesh region while passing through the organic electroluminescent display, which then leads to a blur issue for the background image. In addition, the conventional power line is mostly a mesh structure composed of vertical lines and horizontal lines, and the mesh structure can easily be interfered with a background object having a periodic structure to generate the Moire fringes that is disadvantageous for a transparent display effect.